Soda-lime glass microlens arrays fabricated by laser: Comparison between a nanosecond and a femtosecond IR pulsed laser

• An efficient low-cost process for fabricating microlens arrays on glass is presented.
• The technique is composed by a laser direct-write process and a thermal treatment.
• A microstructuring comparison between femto and nanosecond laser is made.

We present the manufacturing of microlens arrays on soda-lime glass substrates by using two different IR pulsed lasers: a nanosecond Nd:YVO4 laser (1064 nm) and a femtosecond laser based on Ytterbium crystal technology (1030 nm). In both cases, the fabrication technique consists of the combination of a direct-write laser process, followed by a post-thermal treatment assisted by a CO2 laser. Through the analysis of the morphological characteristics of the generated microlenses, the different physical mechanisms involved in the glass ablation process with a nanosecond and a femtosecond laser are studied. In addition, by analyzing the optical features of the microlenses, a better result in terms of the homogeneity and quality of the spot focuses are observed for those microlenses fabricated with the Nd:YVO4 nanosecond laser. Microlens arrays with a diameter of 80 and 90 µm were fabricated.